In many oil wells, gas is dissolved in the oil and when the oil comes to the surface and is exposed to the lower pressure at the surface, the gas bubbles out of the oil. Frequently this gas is not present in the oil in sufficient quantities to warrant storage or transportation of the gas to a pipeline. Since the gas is often sour (contains hydrogen sulphide) and itself may be harmful, regulations require that the gas be burned at the oil well. This process is known as flaring the gas.
To enable the gas to be burned at a safe distance from the oil well itself and to avoid a fire hazard near the ground, the gas must be burned at a relatively high point above the ground. For this purpose, flare stacks are used. These flare stacks may be over 90' high and consequently are exposed to high winds, with the result that the flares frequently go out and require re-igniting.
Ignition itself can be difficult. If a fixed spark gap is used, the spark gap can become corroded and eroded, with the consequence that the spark may be insufficient to re-ignite the flare, particularly in high winds. The inventors have proposed the use of a flexible spark probe (hot electrode) in which a constant gap is maintained between the hot electrode and the grounded electrode even though the flexible probe may be vibrating in the wind.
There is therefore proposed in one aspect of the invention an igniter comprising:
a first probe having a first tip end that may move in normal wind conditions in a substantially planar surface; PA1 a second probe having a second tip end; PA1 one or both of the first and second tip ends being extended at least in a direction parallel to the planar surface, the first tip end being disposed adjacent the second tip end; PA1 whereby upon movement of the first tip end, a substantially constant gap is formed between the first tip end and the second tip end.
Preferably, the second tip end is linear and the first tip end is extended in a direction in the planar surface at an angle to the second tip end, whereby upon movement of the first tip end in the planar surface, a substantially constant gap is formed between the first tip end and the second tip end.
The invention also provides means for mounting the igniter and means for providing an electric pulse to the igniter to form an ignition system.